hi frnds

when i run the top it wil give the following o/p
i want to know what it indicate ....???
what is us,sy,ni,id,wa ,etc .....??
------------------------------- o/p --------------------
Tasks: 551 total, 1 running, 550 sleeping, 0 stopped, 0 zombie
Cpu(s): 6.0%us, 3.2%sy, 0.0%ni, 89.5%id, 0.0%wa, 0.1%hi, 1.2%si, 0.0%st
Mem: 3896296k total, 3678292k used, 218004k free, 325424k buffers
Swap: 8385888k total, 0k used, 8385888k free, 1247808k cached
.......continue.......
------------------------------------------------------------------------------------

thanks